Chemotherapy and Other Systemic Drugs Used to Treat Gynecologic Carcinosarcomas (GCSs): A Retrospective Analysis from Hospital Clínico San Carlos (HCSC), An Academic Referral Centre for Rare Gynecological Malignancies in Madrid, Spain.

BACKGROUND/OBJECTIVES: Gynecologic carcinosarcomas (GCSs) are rare cancers with poor prognoses. In this study, we aimed to analyze the chemotherapy regimens used to treat GCSs at our institution, as well as the patients' outcomes. METHODS: We conducted a retrospective analysis of 62 GCS patients treated at Hospital Clinico san Carlos (HCSC) from 1995 to 2024. RESULTS: Data from 62 GCSs were analyzed. Fifty-two patients (84%) underwent surgery at diagnosis, followed by radiotherapy in 20 (38.5%) endometrial carcinosarcoma (ECS) patients and perioperative chemotherapy in 45 GCS patients (62.6%). After a median follow-up (mFollow-up) of 20 months (0-242 months), 23 GCS patients relapsed and 13 progressed after the first treatment approach, 3 of them almost immediately after surgery. The median time to disease relapse was 6 months (0-225 months) and the median time to disease progression was 0 months (0-25 months). Sixteen of the relapsing patients and fifteen of the patients who were diagnosed at stage IV received systemic treatment with carboplatin and paclitaxel, the most common forms of chemotherapy (used as first-line treatments in eight of the relapsing patients and in seven patients who were in stage IV at diagnosis). GCS patients received up to five lines. The median progression-free survival (mPFS) was 5 months for the first line, and decreased in the following lines. The median overall survival (mOS) was 24 months (13.5-34.5 months) and 11 months (1-226 months) after GCS relapse/progression. CONCLUSIONS: GCS is a rare and aggressive disease with a high recurrence rate after surgery and short progression-free survival (PFS) at advanced stages, even when a combination of oncological therapies are used. (Nevertheless, some patients achieved long disease-free survival). To the best of our knowledge, this is the first publication to provide this valuable data on this rare and aggressive disease, for which phase III and real-world data is scarce.